One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,4)(3,7,8,6)(9,10,13,14)(11,17,19,15)(12,20,21,16)(18,22,24,23)(29,37)(32,34)(35,40)(38,39)(1,3)(2,6)(4,7)(5,8)(10,14)(15,17)(16,20)(22,23)(25,26,30,27)(28,31,36,33)(29,32,37,34)(35,38,40,39)(1,2,5,4)(3,6,8,7)(10,14)(15,17)(16,20)(22,23)(26,27)(31,33)(32,34)(38,39)(2,4)(6,7)(9,10)(11,17)(12,16)(13,14)(15,19)(18,23)(20,21)(22,24)(25,27,30,26)(28,31,36,33)(29,34,37,32)(35,38,40,39)(1,4,5,2)(3,7,8,6)(9,11,13,19)(10,15,14,17)(12,18,21,24)(16,22,20,23)(25,28,30,36)(26,31,27,33)(29,35,37,40)(32,38,34,39)(1,3)(2,6)(4,7)(5,8)(9,12)(10,16)(11,18)(13,21)(14,20)(15,22)(17,23)(19,24)(25,29)(26,32)(27,34)(28,35)(30,37)(31,38)(33,39)(36,40) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.